The widespread application of superconducting magnets has greatly promoted the technical development of cryogenic engineering technology. For the engineering requirements of 100 kW @ 4.5 K ultra-large helium cryogenic system and 1.8K superfluid helium cryogenic system of future "China Fusion Engineering Test Reactor (CFETR)", it is planned to construct a 250 W @ 1.8 K superfluid helium cryogenic system. This paper introduces the benefits of superfluid helium for cooling superconducting magnets, simplified flow chart and key equipment of 1.8 K superfluid helium cryogenic system.